Digestion Flashcards
(72 cards)
The six basic nutrients are
- Carbohydrates
- Fats
- Proteins
- Vitamins
- Minerals
- Water
Macro vs micro nutrients
Macro: Carbohydrates, fats, protein. Large quantities needed by mass
Micro:Vitamins and minerals. Small amounts by mass
Distribution of nutrients male vs female
Male Fem Water 60% 50% Protein 20% 18% Fat 18% 30% Carbs 2% 2%
Word carbohydrate comes from
Carbo: Carbon
Hydrate: Water is made of 2 hydrogen, one oxygen. All carbohydrates contain these elements in that ratio
Monosaccharide
Exist in ratio of one carbon to two hydrogen to one oxygen
What are carbohydrates?
Energy molecules, either sugars or starch
What is starch?
100s of glucose molecules joined together by covalent bonds. Does not taste sweet. Aka amylose (plant)
Glycogen is animal starch. Polysaccharide.
How organisms store glucose. Is insoluble. More branches, less soluble (glycogen)
How does starch begin digestion?
Broken down in mouth by enzyme called salivary amylase. Starch —Salivary amylase, H2O—-> Maltose + energy
What is the formula for glucose, galactose, and fructose?
C6H12O6
What is the formula/makeup of maltose, lactose, and sucrose?
C12H22O11
M: G-G
L: G-g
S: G-F
What is a disaccharide and how are they formed?
Two monosaccharides bonded through dehydration synthesis
G+G –enzyme–>H20 + G-G (Held together with peptide bond)
How are disaccharides converted to monosaccharides?
Hydrolysis:
G-G + H2O –Maltase(etc)–> G + G
How are sugars transported?
They are dissolved in water. They are converted into a transport form that makes them less likely to be metabolized. Usually made into disaccharide.
What is cellulose?
An insoluble starch found widely in plants and it is needed for support and structure of the cell walls. It is the most widely used structural organic material on earth. The bonds between the glucose molecules are more resistant to hydrolysis than starch. Cellulose is digested by enzymes called cellulases. The enzymes are produced by protozoans, invertebrates in the digestive tract. Cannot be digested by humans.
Fats and energy
Fats are composed of the same atoms as carbohydrates but in a different arrangement.
Fats provide 2x as much energy per gram than either carbohydrates or proteins
Fats can be formed when the body converts excess energy from carbohydrates or proteins into fat in the liver
Important functions of fats
- source of energy
- to dissolve fat soluble vitamins
- fat under our skin, subcutaneous fat, helps insulate
- deep internal fat cushions and protects organs
Adverse effects of fat
- excess leads to obesity
- obesity places strain on the heart, muscles, and other body systems
- emotional distress
Structure of fats
Two parts:
Glycerol: Backbone
Fatty acid: Mono, Di, or Triglyceride
Saturated vs. Unsaturated fats
Sat: -solid at room temp -max amount of hydrogen bonded to carbon -higher melting point Ex. Steric acid -linear molecule
Unsat:
- liquid at room temp
- Fewer hydrogen atoms bonded to carbon, double bonds present
- lower melting point
- double bonds cause bends in molecule
Trans: Unsat with qualities of Sat. Hydrogens on opposite sides creating linear molecule
Cholesterol
- white waxy substance
- produced by liver, transported by bloodstream
- high blood cholesterol levels are linked to increase risk of heart disease
- can cling to walls of blood vessels and reduce blood flow (arteriosclerosis) Can lead to heart attack
- found in animal products
- polyunsaturated fats tend to lower blood cholesterol levels. Saturated tend to increase blood cholesterol levels
Functions of proteins
- building, repair, maintenance of tissue especially during growth spurts during first two years after birth and during adolescence
- form a major part of muscles, internal organs, the brain, nerves and skin
- play important role in fluid balance
- needed to make enzymes, antibodies, and hormones
- maintain pH balance
Structure of protiens
- 100s to 1000s of amino acids
- amino acids are composed of carbon, hydrogen, oxygen, nitrogen, and occasionally sulfur
- 20 different kinds
- the order and number of amino acids determine the type of protein
Essential vs. nonessential amino acids
Essential: Cannot be synthesized and must be included in diet. 8. Lack of any can block production of proteins. Proteins that contain all the essential amino acids are known as complete proteins. Proteins that are lacking are called incomplete. Incomplete that can be matched to obtain all the essentials are called complementary
Non: Can be synthesized from carbohydrates, fats, and amino acids
Proteins as an energy source
- proteins are not stored like carbohydrates or fats for later use
- if body requires amino acids which are not available in diet tissue proteins are broken down. Extra amino acids are used as energy or lost.
- if amount available is greater than amount needed converted into glucose and then fat. During the conversion process the nitrogen is removed and excreted in urine. The body cannot convert fats to protein because of this.
- inefficient